On September 14th, 2017, we published revised versions of our Privacy Policy, Terms of Service and Website Use Policy and published a Cookie Policy. Your continued use of Lynda.com means you agree to these revised documents, so please take a few minutes to read and understand them.

EFM1: Basic frequency modulation

- [Instructor] Okay the next instrument we haveto talk about is EFM, and I really likeworking with this one because it uses a synthesis method,known as frequency modulation, or FM.This is a synthesis method that was developed byJohn Chowning, back in the day, in the 70's,and was popularized by the Yamaha DX7, which was a hugesuccess in the synthesizer market, because it hadsuch a cool, new sound.So let's go through some of these presets,we'll talk about the nuts and bolts of frequencymodulation in a second, but I would like to take a lookat some of these presets, so let's start out withbass, because some of the bass is a lot of fun.

We can get these cool rubbery sounds.(bass notes)as you can hear, frequency modulation is great forcreating things that are very, very expressive, and alsohave a lot of texture to them.(bass notes)let's go through, a stereo bass.

Let's check out some of the pads as well.(synthesizer)A lot of texture there, a lot of stuff to work with.Let's check out some of these FM leads or keyboardsor things like that, actually let's check out the bells,because one of the things that we can do very nicely,(bell chimes)is create metallic sounds using frequency modulation.So, one of the things that you might be noticing,I'm just going to go back to the default sound here,one of the things you might be noticing here,is that there aren't too many new characters here.

You might also be noticing, that there isn't a filter.Frequency modulation is sort of the opposite ofsubtractive synthesis, in the sense that, insteadof taking a band wave, like a Sawtooth or a square,we're actually creating a sound, we're building it fromthe ground up, so in the past, what we've done is we'vetaken our Sawtooths, our square waves, and we've chippedaway at them over time, using envelopes and usingfilters and things like that, and what we wind up being ableto do with our frequency modulating synthesizer, is kindof grow a sound, it's a really cool approach, so(notes)right off the bat we have a little bit of FM going,and essentially what we're doing here, is we're takingtwo oscillators, one is known as the carrier,that's the audio signal, and then one is known asthe modulator, that's the control signal here.

And, we're just using the modulator to modulate the pitchof the carrier, or the frequency.So, think of the carrier as being the one that's pluggedinto the audio chain, that's the one we're listening to,but, think of making a vibrato with an LFO, as we'vedone in the past.Making that vibrato you're using an LFO to move thepitch of the audio oscillator up and down,kind of slowly, slowly enough that we can actually hear it.Now here's the thing about frequency modulation,is that we're doing it so fast, we can't hear theindividual movements anymore, what we wind up isactually creating these side bands and these tonesand these textures because it's moving at audio rate.

And so, we have a specific set of controls that wegenerally use when we're talking about frequency modulation.So, first of all let's talk about the carrier.It's over here on the right, and we can find it,(notes)now, I've turned FM all the way down.(notes)okay, and the first thing I'm going to do is just movemy harmonic motion over here.I'll have the ability now,to change the pitch of my carrier over here.

The carrier pitch and the modulator pitch are usingwhat's called a ratio, so we have a C:M ratio of six to one,it means that the carrier is at a ratio of sixand the modulator is at a ratio of one,and what this actually refers to, are these numbersthat we're using here, which represent differentdegrees of the harmonic series.So when we were talking about the harmonic series before,building a Sawtooth wave or a square wave,we have these harmonics that make up a sort ofchord, that create a pitch that we can hear,that has some texture to it, some tambour.

We use the harmonic series as a tuning tool for ourdifferent oscillators in frequency modulation.So I can move the carrier up and down,(notes)and you notice that it is changing the pitchand then we can also turn the modulator up and down.(notes)okay, now we said before we don't actually havea filter in here, what we're using to create thatbrightness, those sidebands, is the modulator here,so we have an envelope for the modulator, I'm just going toturn the volume envelope up to full sustain.

So that we can really hear what the modulatoris doing here.So if I turn all the modulator stuff down, and we'renot using it, here we don't have much going on,let me turn the harmonic up to one.There we go, we can hear that this is actuallya sign wave that we're using.Or something very close to it.Okay, we have an FM depth knob over here,which is actually controlling the extent to whichthe modulation envelope is controlling the FM amount.So, the FM amount is essentially how wide that modulationis, if we're modulating pitch and we're doing it veryslowly with a vibrato, it tends to be very subtle,like a third of a step or something like that.

That's a nice vibrato area, if we're using an LFOto control the frequency of an oscillator.In this case, with frequency modulation, we callthe amplitude of the modulator the index of modulation.Now you don't have to worry about that here, this isa pretty basic frequency modulating synthesizer,and they just have the term FM put here,and so we turn this knob up if we want to hear more FM.And this is a very simple setup right now,essentially what we've got, is a carrier and a modulator,both the same pitch, you see we have a one on both sides,and so what that does, is it just creates some verysimple side bands as we up the amount of modulation.

(notes)Now I can also change the ratio of the modulator.(notes)okay, this is kind of cool, we can also change thewave of the modulator over here.(very synthesized notes)now you can hear, as I push this up, we're gettingbuzzier and buzzier, so I would imagine that overto the far left we have a sign wave, or somethingvery similar.

So we get different flavors as we move that wave around.

Resume Transcript Auto-Scroll

Author

Released

3/16/2017

The virtual instruments inside Logic Pro X are some of the main tools used for creating the music we know and hear everywhere. In this course, author Evan Sutton explores ways you can use the virtual instruments found in this industry-leading, professional audio product from Apple. Evan shares a comprehensive examination of the vintage instruments in Logic, including the B3 and Clav, basic synthesizers like the ES 1 Subtractive Synth and ES P Polyphonic Synth, advanced synthesizers including the ES 2 Hybrid Synth and Retro Synth, the EXS24 sampler, and other major instruments including Alchemy, Sculpture, Drum Kit Designer, and Ultrabeat. He covers working with oscillators and filters, understanding modulation, designing sounds, routing, mapping, slicing, and much more.